SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c0d883548faddf76026a470f18d959d85760c2068c945855c5d30d76bf5b9c1' 
  AND token = 'JXdxaJWnxM7g0wvpAofxwFdrVYd6XtiX7iLPLIJncLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}